Regge behaviors in orbitally excited spectroscopy of charmed and bottom baryons

Stimulated by recent progress made by the LHCb Collaboration in discoveries of new bottom baryons, e.g., the ${\mathrm{\Xi }}_b(6227{)}^{-}$ and the ${\mathrm{\Sigma }}_b(6097{)}^{\pm }$, we reexamine the orbitally excited spectrum of the charmed and bottom baryons using the Regge approach in the heavy quark-diquark picture. The results indicate that the spin-averaged mass spectrum of the orbitally excited charmed and bottom baryons can be described by a linear Regge relation, which is derived from the rotating QCD string model. By giving further mass-splitting analysis of spin-dependent interactions, we explain the baryons ${\mathrm{\Xi }}_b(6227{)}^{-}$ and the ${\mathrm{\Sigma }}_b(6097{)}^{\pm }$, and the ${\mathrm{\Sigma }}_c(2800)$ and ${\mathrm{\Xi }}_c^{\prime }(2930)$ to be the $1P$-wave baryons, all with the spin-parity $J^P=3/2^{-}$ preferably. Mass prediction of the bottom baryon ${\mathrm{\Xi }}_b$ in its $P$-wave- and $D$-waves are presented, providing clues for the coming experiments like the LHCb to find them.

Figure 1

The masses of the $P$-wave ${\mathrm{\Sigma }}_c$ against the parameter $b$.

Figure 2

The masses of the $P$-wave ${\mathrm{\Xi }}_c^{\prime }$ against the parameter $b$.

Figure 3

The masses of the $P$-wave ${\mathrm{\Sigma }}_b$ against the parameter $b$.

Figure 4

The masses of the $P$-wave ${\mathrm{\Xi }}_b^{\prime }$ against the parameter $b$.